A 23-year-old woman is taking legal action against an NHS clinic because she was not challenged more by staff to avoid gender reassignment treatment as a teenager.

Kiera Bell’s case will now proceed to a full hearing against the Tavistock and Portman NHS Trust after a judge agreed that the complainant had sufficient grounds to prompt a judicial review.

Bell’s legal team claim that children cannot give fully informed consent to puberty-blocking drugs and other steps on the road to surgery, and that Bell was “rushed” through the process at the clinic.

A biological female who believed she was male, Bell was prescribed puberty-blockers at Tavistock Gender-Identity Development Service after three one-hour appointments at the age of sixteen, but claims she “should have been challenged on the proposals or the claims that I was making for myself.”

One year later Bell was prescribed testosterone, bringing on facial hair and a deep voice, and then, at twenty, Bell had her breasts removed.

Bell decided to stop taking cross-sex hormones last year after feeling suicidal following the surgery and years of hormone treatment. Having now accepted that her sex is female, she says her anger remains that the treatment has left her with irreversibly damaged physical and mental health.

“I was allowed to run with this idea that I had, almost like a fantasy, as a teenager…. and it has affected me in the long run as an adult.”

“I’m very young. I’ve only just stepped into adulthood and I have to deal with this kind of burden or radical difference – in comparison to others at least…So I think it’s up to these institutions, like the Tavistock, to step in and make children reconsider what they are saying, because it is a life-altering path.”

Bell says the gender transition was a “coping mechanism” and alleges that there was no real attempt by Tavistock to solve the mental health issues underlying her teenage gender dysphoria.

Another claimant, known as Mum A, will join Bell’s case as her 15-year-old autistic daughter, whom she says cannot offer consent, awaits treatment at the clinic.

Some 35 psychologists have reportedly resigned from Tavistock clinic in the past three years, with some questioning the practice of giving hormonal treatment to children with gender dysphoria. There are claims that children as young as 12 have been given drugs at the clinic.

Consultant clinical psychologist at Tavistock Dr. Polly Carmichael said that their approach is much more cautious than suggested, and that fewer than half of their teenage patients go onto to take puberty blockers or hormones.

“This is a really complex area with strong feelings on all sides. And at its centre, the young people we work with – they come to us in often really great distress around their sense of themselves,” she told the BBC.

“We’re talking about identity here, their identity, and a feeling that their gender identity does not match that body.”

The landmark case, which could change the way childhood gender dysphoria is treated in the UK, will be heard later this year at the High Court.